"All this region is very level and full of forests, vines and butternut trees. No Christian has ever visited this land and we had all the misery of the world trying to paddle the river upstream." Samuel de Champlain

During a conference call with Vermont Yankee staff last week regarding the ongoing groundwater contamination investigation at the plant, technicians said the source is still unknown.

Pressure tests and boroscope exams have been completed on two of five underground lines in the vicinity of the RAD Waste Building at the Vermont Yankee nuclear plant in Vernon, according to Nuclear Regulatory Commission spokesman Neil Sheehan.

The plant stack sump discharge line and the Augmented Off-gas Delay Pipe Drain Line have also been checked, he said.

One possibility of the source could be a phenomenon called rainout.

Sheehan said rainout refers to what happens when an airborne release of tritium is occurring from the plant, typically via the plant stack, at the same time there is precipitation.

"The tritium can be deposited on plant buildings or the ground and subsequent rainfall can then wash that contamination into the groundwater at the site," he wrote in an e-mail. "When we are seeing fluctuations in groundwater contamination, particularly at the low levels being measured in GZ-24S."

The latest well sample showed 1,000 picocuries per liter of tritium, down from 8,139 on Jan. 26, Sheehan wrote.

Bill Irwin, the state’s chief of radiological health, said rainout can also affect the plant’s sewer system but that all manholes at the plant showed no signs of tritium.

The real question, Irwin said, is "why the levels have been going down fairly steadily since the beginning of this year."

There’s still no understanding why the leak is happening but there is a plethora of options that are being investigated, Irwin said.

More than 320,000 gallons have been extracted from monitoring wells, 12,800 gallons since January, Sheehan wrote.

Vermont Yankee’s manager of communication, Larry Smith, said rainout is something the plant technicians are monitoring and testing of the three other underground lines is planned for this month."

I'm the second generation of my family that lives in Richelieu, Quebec, in Canada. My family tree, both from my mother's and my father's side, has its roots in Quebec since the beginning of the 1600s: my ancestors crossed the ocean from France, leaving Perche and Normandy behind them. Both French AND English are my mother tongues: I learned to talk in both languages when I was a baby, and both my parents were perfectly bilingual too.